bone densitometry correct answers the art and science of measuring the bone mineral content and
bone mineral density of specific skeletal sites or the entire body
bone measurement values correct answers used to assess bone strength, diagnose diseases
associated with low bone density (like osteoporosis), monitor the effects of therapy for such
diseases, and predict risk of future fractures
dual x-ray absorptionmetry (DXA) correct answers the most versatile technique for bone
densitometry
-low radiation dose
-wide availability
-ease of use
-short scan time
-high-resolution images
-good precision
-stable calibration correct answers the DXA scan has the advantages of--
subtraction technique correct answers the differences bw DXA and radiography are that DXA
uses a what?
photon energies correct answers dual x-ray means that to eliminate the contributions of soft
tissue and and measure the x-rat attenuation of bone alone, you do this by scanning at two
different x-ray __ __
diagnosis correct answers DXA are only used for the purpose of confirming correct positioning
of the pt and correct placement of the region of interest, it is not used for?
three correct answers how many DXA manufacturers are in the US?
lower correct answers the effective radiation dose for DXA is considerably __ than for
radiography
osteoporosis correct answers an undetected and overlooked disease until the 1920s when
radiography revealed the detection of decreased density in bones
radiographic absorpitiometry correct answers involved taking a radiograph of bone with a known
standard placed and optically comparing the densities
radiogammetry correct answers was introduced in the 1960s partly in response to the
measurements of bone loss performed in astronauts
decreases correct answers with radiogammetry, it was found that as bone loss progresses, the
thickness of the outer shell of the small tubular bones ___ as the inner cavity enlarges
, quantitive computed tomography correct answers adapted in the late 1970s with the use of
specialized software and reference phantoms which allowed for quantitive measurements of the
central area of the vertebral body where early bone loss occurs
single photon absorptiometry(SPA)/dual photon absorptiometry (DPA) correct answers
introduced in the 70s and 80s and is based on the physics principle similar to DXA; this relies on
a water bath to eliminate the effects of soft tissue
DPA correct answers used photons of 2 energies and was used to assess cites in the central
skeleton (l-spine and prox femur)
collimated scintillation counter correct answers with the DPA, the intensity of the attenuated
beam was measured by a ______, and the bone mineral was quantified
the first commercial DXA scanner correct answers first introduced in 1987 and used a
radioisotope for its source before being replaced by an x-ray tube
-smaller
-more portable
-less complex correct answers in the late 90s, DXA scanners have become more what?
hip, spine correct answers DXA of the _ and _ is still the most widely accepted method for
measuring bone density and remains a superior procedure for monitoring the effects of therapy
-supports the body and protects vital organs so that movement, communication, and life
processes can be carried out
-manufactures red blood cells
-stores the minerals that are necessary for life, including calcium and phosphate correct answers
the skeleton serves the following purposes--
cortical. trabecular correct answers the 2 basic types of bone
cortical bone correct answers forms the dense, compact outer shell of all bones as well as the
shafts of the long bones
trabecular bone correct answers the delicate, lattice-work structure within bones that add strength
without excessive weight
25%, 75% correct answers in the central skeletal system, _ percent of bone volume is specific
bone tissue and _ percent is marrow and fat
40%, 60% correct answers the specific bone tissue is _ organic matter and _ bone mineral
bone mineral correct answers deposited as hard, brittle crystals in flexible collagen and gives
bone its rigidity and strength